I don’t think it should be multi-channel. I said that the channel layout in the device has probably nothing to do with the issue. As Guido also has 5.1 Flacs it would be useless of continuing switching the Channel Mapping setup.
If Guido gets static noise that indicates as if the hidden code in the DTS is not sent to the receiver.
That’s why I’m curious what Roon says about the Audio information.